Process Simulation & Optimisation

Our key difference is that we can bring together our expertise in process simulation and our extensive real-world process engineering experience to help you overcome your most difficult processing challenges. Flex Process use many different modelling and simulation techniques to support our clients, depending on your needs we can perform steady state or dynamic modelling, dispersion modelling, CFD or FEA etc. Flex Process is a leader in the field of dynamic process simulation and this technique often provides a cost-effective approach to solving our clients’ problems.

Flex Process apply advanced modelling techniques to troubleshoot your plant, reverse engineer its current design, optimise plant operating conditions, improve efficiency and yields, ensure safe operation, and reduce your CAPEX, OPEX, energy costs, and emissions. We can help you optimise and modify your process, and help you develop and test new operating procedures in a real-time simulation.

There are numerous plants operating worldwide where no one truly understands the process. Perhaps there’s been too many modifications or feed changes over the years to trust the original mass balance, or perhaps the paperwork has been lost or degraded in storage or key personnel have left. Our simulation tools can make sure you understand your process fully, with a full up to date mass and energy balance, and dynamic models that replicate real operating conditions. We can help you solve difficult and complex process issues and understand your plant better, including using our simulation for training.

Our experience shows that most plants, even new ones can improve their efficiency by 5 or relatively easily, using this technology. Surprisingly, new builds recently delivered by EPCs are especially lucrative for this, since the EPC focus was on getting the plant built on time and on budget, and optimising the overall process was often not done.

Talk to us about how our advanced simulation expertise can help you.

Flex Process is a leader in the field of dynamic process simulation and this technique often provides a cost-effective approach to solving our clients’ problems.  We firmly believe that the future of process engineering is in advanced simulation techniques like dynamic modelling which is a central pillar supporting many of our activities across all our service offerings.

We use the latest dynamic simulation techniques to troubleshoot your plant, reverse engineer its current design, optimise plant operating conditions, improve efficiency and yields, ensure safe operation, and reduce your CAPEX, OPEX, energy costs, and emissions. This technique is incredibly versatile and can be used to solve many different processing challenges. Often, we find that the dynamic simulation model is the final step in a digital journey our clients are on to modernise and improve their plant operations through digital transformation. We often work with clients in a staged or phased fashion applying small digitalization initiatives progressively through incremental small achievable steps that bring immediate benefits while continuing to move towards more ambitious targets such as a digital twin of their entire facility.

Flex Process has extensive experience with assisting our clients using this approach. This starts at the basic level where we have helped with capturing and digitalizing basic plant information, through reverse engineering where we create or recreate basic plant information such as process flow diagrams, data sheets, and P&IDs etc., and eventually to advanced 3D models and dynamic simulations which allow us to thoroughly understand the plant and propose changes that greatly improve its operation and optimise its performance. Often this starts at a single location where we tackle a single plant problem or project on a small part of the process, reverse engineering the associated process operating and design details, and solving the problem. Then we tackle other problems elsewhere on the plant, and after a few years we have reverse engineered and developed models of much of the facility. Eventually it makes sense to join the models together to end up with a full model of the entire plant or facility.

Talk to us about how our experienced engineers can partner with you to resolve your pain points using our advanced simulation tools such as dynamic simulation cost effectively. We are always finding new ways to use dynamic modelling expertise; the following is where we use it most:

Process Development & Optimisation 

  • Conceptual process development.
  • Design support to projects.
  • Emissions reduction.
  • Energy optimisation and energy efficiency.
  • Plant capacity debottlenecking.
  • Plant operating optimisation.
  • Training simulators.
  • Process troubleshooting.
  • Process control.
  • Batch reactor modelling.
  • Assessment of new technologies.

Digitisation, Digitalisation and Digital Transformation

  • Digital twins.
  • Reverse engineering.
  • Recreation of plant information, plant data, data sheets etc.
  • PFD and P&ID development.
  • Foundation data/Process Safety information.
  • Plant data analysis.
  • KPIs and operating targets.

Process Safety

  • Reverse engineering of process details and process safety information.
  • Process design and design verification.
  • Alarm and trip settings including process safety calculations, verification of safe operating envelope and safe trip system design.
  • Scenario development (HAZOPs and other safety studies).
  • Relief, Flare, and de-pressuring studies.
  • Safe operating procedures including start-up and shutdown.
  • Compressor operating controls and shutdown.

Decarbonisation and Net Zero

  • Decarbonisation & GHG emissions reductions.
  • Energy optimisation and energy efficiency.
  • Evaluation of new technologies (green chemistry and green engineering)

Process simulation is an essential tool when looking at new processes.  It provides 1) an in-depth understanding of the thermodynamics and 2) refines the process concept through delivery of a heat and mass balance.   The modelling of heat and mass flows allows the scoping sizing of equipment that provides basic plant footprint information and early stage capital equipment costs and energy operating costs.

Conceptual process development

Process scale up

When technologies are transferred from laboratory to pilot scale to full scale there can be many pitfalls.  Some of these can be reduced by having a better understanding of how the process would scale up into commercially available equipment.  Our practical advice provided in the early stages of a project concerning choice of equipment or technology, can have significant impact on the final capital cost and viability of the scale up notwithstanding the benefits to process safety through lower inventory or safer operating conditions.  This advice would be based on our real plant experience backed by cutting edge simulation technology in steady state, dynamic and fluid dynamics.

When considering process scale up, we consider volume to surface area effects such as heat losses, mixing and choice of agitator, heat transfer, pumping rates and the control scheme.

We inherently look at how a process can be optimised through simulation providing higher throughput, lower batch cycle times and lower energy costs.

Our design team have years of experience tackling large or small projects, brown or greenfield, conceptual design, FEED, detailed engineering, and operational enhancements. New build designs are optimised to get the right balance of capital and operating costs, environmental and safety performance. Existing operating plant can be modified to squeeze out more capacity and optimise yields and energy costs. Our advanced modelling techniques and innovative approach ensure you get value for your money and a safe, efficient, and reliable plant. We can provide an outsource simulation resource for your projects or simply a simulation design checking service using our expertise to prove dynamics to demonstrate that your concepts will work as intended to avoid any potential start up issues or hidden bottlenecks that do not reveal themselves in the normal design process.  We build a replica of your process and test it, so you can have confidence in your design.  We may also make some recommendations that enhance operation and save you significant operating costs.

design support


When you operate a large, complex process, it is sometimes hard to get to grips with the overall energy balance.  You may already have tools that monitor consumption, but they never seem to balance and you can see the problems but cannot visualise the solution.  As consultants, we understand that you understand your process and that making changes needs to be practical and cost effective.  We advocate the use of process simulation models that match your process, allowing you to visualise solutions with our help.  Models sometimes reveal the cause of imbalance, through locating faulty plant instrumentation, prompting further investigation.  The characteristics of energy flows can be quickly observed, saving you significant time and allowing you more time to solve the problems rather than analysing them.

We advise on Pinch Analysis, the methodology used to minimise energy consumption by calculating thermodynamically feasible energy targets and achieving them by optimising heat recovery systems, energy supply methods and process operating conditions.

Energy integration

Plant capacity

Plant and Process Engineers are great at optimising their plants through increase reliability and adjusting control parameters.  We can take it a stage further by optimising those parameters that are hidden and not obvious until they are simulated.  We have shown that we can increase throughput by 10% just be a thorough understanding of the process from the inside out.  Moreover, we can test out our ideas virtually to ensure that there is a clear, safe pathway to making the changes, giving you peace of mind.

Every plant should have a realistic training simulator to allow new starters to quickly come up to speed, or to make the plant safer by ensuring that everyone responds in the correct way to an emergency.  There are often other financial benefits to training: such as ensuring that every shift follows the most efficient operating regime or equipment is not operated outside its design range increasing plant reliability.  We can provide a training simulator that fits your budget and often these can be used for other engineering studies adding even more value.

Dynamic simulation

Mechanical Assessments & Pipe Stress Analysis

We analyse your plant data and use dynamic models to replicate plant symptoms that quickly lead us to the cause of problem.  We will then provide practical solutions to help you continue plant production.  Sometimes the symptoms are misleading and need to be carefully analysed to find the root case.

Process control is a multi-disciplinary field where advanced simulation can have a great impact on the operation of your plant by bringing together the expertise of your process, control, instrumentation, and operations people, and incorporating that experience together with historical operating data into an accurate simulation of your plant. We can propose new control concepts and optimise controller tuning settings that will save you significant time at plant commissioning and lead to steadier operation and optimised operation.  We can help you solve problems with conflicting controllers, difficult control schemes, poorly set alarms, and unexpected trips. We can also provide your engineers with a platform to perform a virtual check-out of their PLC and DCS code, tune their PID control settings, or just try out new ideas, without any disruption to your actual plant. Existing control schemes can be reverse engineered through dynamic modelling that allows you to recreate control concepts for legacy plant.  Simulation models can be linked to control software to check software code in a virtual Factory Acceptance Test (FAT).

Process Control

Batch reactor modelling

We can model batch reactors dynamically to ensure that your process meets the required cycle time and throughput.  We have shown that significant savings can be made by optimising the heating and cooling systems, and control scheme.  We would typically model the liquid heated by a jacket, batch distillation and mixing.  All stages of the batch process can be modelled to replicate the proposed sequence logic.  We can also simulate the reactor relief cases such as thermal runaway and external fire, sizing your relief system and dump tank.  We also show that vapour emissions are safe through PHAST dispersion modelling.

We can support the development of new process technologies through the construction of steady state, hydraulic and dynamic models that encompass the correct thermodynamics, reaction kinetics or rate based separation.  We offer a progressive modelling service that meets your needs, with the level of fidelity which is fit for purpose for the project stage that you are at.  Activities include:

·         Correct selection of thermodynamic models

·         Feed characterisation

·         Conceptual heat and mass balance with a range of feedstock

·         Scoping sizing of equipment, including capital costing

·         Utility demands

·         Early stage assessment of safety scenarios such as loss of containment

·         Impact of integration into existing processes.


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